Project Logicality: The Reductio Ad Absurdum – Invalid & Valid
Posted by Troy Loy
Let’s suppose that there are two men engaged in an argument, we’ll call them Mr. A and Mr. B.
They’re engaged in a rather spirited discussion on psi-phenomena, and Mr. A argues that psi is unlikely to exist because truly compelling evidence, in the form of successful replications of psi, regardless of the beliefs or level of enthusiasm of those attempting the replication of the initial studies, does not currently exist.
Note that he is not saying he doesn’t think it’s real because he hasn’t personally experienced it nor seen concrete, direct evidence of its existence, but that despite the immense volume of evidence in the literature, it just isn’t very convincing by reasonable scientific standards, and so one should remain skeptical for the time being.
Nor is he arguing that it’s impossible, only unlikely to exist until convincing evidence under reasonable conditions by reasonably objective research workers indicates otherwise.
In his rebuttal, Mr. B argues that Mr. A, in thinking that psi probably isn’t real, must also believe that dark energy and dark matter must not exist, because Mr. A hasn’t seen them either, and that he must therefore believe that 90% of the universe must not exist.
Mr. A said nothing about needing to see psi himself, only that convincing evidence obtained under adequate conditions by non-believers in psi is not there, not yet, saying nothing at all about the evidence needed to establish dark matter or dark energy, both of which have different evidential requirements than psi does, for which almost the entire body of data consists of statistical quirks, convincing or not.
Mr. A’s argument has, as can be seen, been misrepresented, and in such a way as to carry it to an absurd conclusion, the claim that by his own reasoning, most of the universe doesn’t exist.
That last was an example of a fallacious Reductio ad absurdum, and of course there was probably much more said than simply the above. But Mr. B’s argument was fallacious because it led to an absurd conclusion without using the actual chain of reasoning of Mr. A’s argument, by misrepresenting that argument as a straw person.
Later, Mr. A and Mr. B get into a discussion of the nature of reality, in which Mr. B, not liking the direction of the argument, responds to what he feels are the overly absolutist statements of his opponent, in exasperation saying in a rather postmodern fashion, “Reality is nothing!”
There are several ways that this can be interpreted, but in this case, a clarification is not offered, and Mr. A cannot read minds nor thinks at the time to ask for a clarification, so the most likely interpretation, that B is claiming reality doesn’t exist, will have to do.
What does this mean? Can we carry this claim to it’s ultimate conclusion without merely misrepresenting it?
What is reality? And I don’t mean what is its ultimate nature in fact, but what is the meaning of the word? How is it used?
Reality, by definition, is that which can truly be said to exist, no matter it’s nature or other properties:
a=a: reality is real.
To be real, this quality of existing is essential, whether the thing existing is directly observable or not. If something doesn’t exist, then it’s not part of reality, and if it’s not even imagined, it’s not fantasy either.
What is everything that is real?
We call it the Universe, or the Cosmos, take your pick, though myself, I’m partial to the latter, though for this discussion I’ll use “universe” for the totality of existence.
To say that reality is nothing, in this context implies that the universe doesn’t exist, 100% of it, not just 90% in the straw person argument above, since the universe is everything, with or without any supplementation to it by anything allegedly supernatural.
But if the universe is everything that exists, and everything currently within and originating within the universe, by definition existing as part of its totality, and therefore part of all reality…
Hmmm… I smell something funny about this, don’t you?..
If the ‘reality does not exist’ interpretation holds and the claim were true, then the claim could never be made, since neither of the two persons would even exist themselves in order to have their argument.
But if Mr. B exists to make his argument to Mr. A, and Mr. A exists to hear the argument, then the claim, assuming this interpretation, is simply, obviously, and demonstrably false.
Clearly this is an unacceptable conclusion, at least until such time as Mr. B offers a clarification of his statement that requires a different interpretation of what he said, we must assume what we did know and thus consider this a valid Reductio ad absurdum.
But personal debates among argumentative friends are often messy, impromptu, with little if any ‘rehearsal’ or ‘practice’ beforehand, and unless both are skilled arguers, it is unlikely that normative standards or ideals will reasonably be met without time and practice.
This is just one of the hazards of personal arguments, but it’s something that can be improved if done systematically and with time, skillfully and instinctively, but the rewards of rich and confident testing of our knowledge by argumentation far outstrip any annoyance that may result in the beginning.